There are many reasons why the bones in the leg may ring, but the most common ones are the following: First, there is osteoarthritis in the knee joint, especially if the osteoarthritis is very serious and the articular cartilage is peeling off, it is easy to make a ringing sound when moving the leg. Secondly, if the patient has a free body in the joint, there will be a ringing sound when moving the leg, and if the patient has meniscal damage, there will be a ringing sound when moving the leg. In order to clarify what is causing this condition, some auxiliary tests are needed to make a definite diagnosis, such as a local MRI. If the bones are rattling due to the presence of free bodies in the joint, it is necessary for such patients to actively undergo arthroscopic surgery to remove the free bodies.